84 Reviews—Geology of Bodmin and St. Austell. 
pauses in the downward displacement of the local limit of subacrial 
degradation ’’. 
The Clay-with-flints, the Valley gravels, and Alluvial deposits are 
duly described, and there is an excellent chapter on Economic Geology. 
The Memoir throughout bears evidence of much diligent research, 
and adds largely to our knowledge. The author, moreover, has 
earefully studied the works of other geologists, and does full justice 
to their labours. The only misprint we notice is H. W. Fitton for 
We He Bitton. 
I1.—Tuae Groroay oF tHE Country Around Bopmin AnD Sr. AUSTELL. 
By W. A. E. Ussurer, G. Barrow, and D. A. MacAnisrrr, with 
Notes on the Petrology of the Igneous Rocks by Dr. J. 8. Frerr. 
8vo; pp. vi, 201, with 3 plates and 34 text-illustrations. London, 
1909. Price 4s. 
fWVHIS Memoir is descriptive of the one-inch colour-printed map. 
Sheet 347, which takes in the area from Bodmin on the north 
to the coast at Fowey and St. Austell Bay on the south. The greater 
portion of this country is occupied by Lower Devonian rocks and the 
bold granite mass of St. Austell and Hensbarrow, with a tract of 
Middle Devonian slates on the north-east. The oldest Devonian 
rocks, grouped as Dartmouth Slates, contain fish-remains of Lower 
Old Red Sandstone type, and the rocks appear in an anticline along 
the eastern coast to the north of Fowey, and thence extend to near 
Lostwithiel. They are bordered by the Meadfoot Beds, beyond which 
are the Staddon and Grampound Grits. ‘The coloration of the map. 
suggests that the Staddon Grit on the north and the Grampound 
Grit on the south are equivalent strata on the opposite sides of the 
anticline. This view is supported by Mr. C. Reid, but is not accepted 
by Mr. Ussher, who regards the Grampound Grit Series as representing 
the marginal conditions of lower beds in the Meadfoot Group, perhaps 
equivalent to the Looe Grits. The Meadfoot Beds have yielded 
a number of fossils, but so poorly preserved that most of the species 
and many of the genera collected by the Geological Survey are 
doubtfully identified. Fossils throw no light on the disputed 
succession, as none are recorded from the Grampound or Staddon Grits. 
The Middle Devonian slates are stated to be fossiliferous, though 
“it is very seldom that anything but crimoid markings can be 
distinguished ”’. 
The region therefrom is not one to attract the student of Devonian 
paleontology; but a great step in advance over the older map has 
been made in the insertion of the geological subdivisions now 
depicted, while the long experience gained by Mr. Ussher has enabled 
him to correlate them with the subdivisions which he has traced step. 
by step from Eastern Devonshire. 
The granite areas have been mapped out in much more detail than 
in the original geological survey map, and the metamorphic aureole in 
the bordering Devonian rocks, described mainly by Mr. Barrow and _ 
Dr. Flett, has been more definitely indicated. Dr. Flett has dealt 
generally with the pneumatolytic alteration of the granite, observing 
that the changes produced by vapours passing through the rock, after 
